"We talk all the time": Wozniacki on relationship with Serena Williams, says she watched her match with Brady at US Open

A theme of Caroline Wozniacki's resurgence has been her relationship with Serena Williams, her rival previously but now a close friend.

Wozniacki reached the Last 16 at the US Open where she will play Coco Gauff and she admitted that she had an onlooker albeit back at home in the form of Serena Williams.

She also in a way had a hand in Wozniacki's comeback with the former World No.1 not thinking about it a year ago until she wanted to watch her retirement and then stepped on the court again.

She now finds herself in the latter stages of a Grand Slam in only her third tournament back and the fire and desire is still very much there.

"Yeah, I talk to her all the time. She's obviously busy now, as well. But we talk all the time. She watched my match today. But last year I was pregnant. I was heavily pregnant, I want to say - what, are we in September - I was eight months pregnant. I was just here to support my friend. Obviously I worked with ESPN. I was doing a lot of commentating and studio stuff," she said.

"I really wanted to support her in her last tournament. That was something very special. I wasn't really thinking about my own comeback at that point. I was trying to figure out how I'm going to handle two kids (smiling). It's been cool that after James was born and I went on court, all of a sudden I go, Okay, well, let's give it a try. Now we're here, and that's pretty special," she added.